In the United States, telephone service is provided by multiple providers or carriers. Some calls are handled by one service provider, e.g., a local call completed between two wired telephone stations. Other calls, e.g., long-distance calls, require multiple service providers to cooperate for their completion.
The initial carrier providing telephone service is a local service provider, illustratively a local exchange carrier (LEC), such as New Jersey Bell, but also including cellular (wireless), cable and any so-called "dial-tone provider" or "first contact service provider", all such being referred to herein as local service providers. The second carrier is typically, but not necessarily, a long-distance-or so-called interexchange--telephone carrier. For example, presently, for a long-distance telephone call between wired telephone subscribers, the local service providers serving the calling and called telephones are LECs which are interconnected by a long-distance, or interexchange, carrier (IXC). In the United States, AT&T, MCI and Sprint axe three such IXCs. In another example, for a local call from a mobile telephone to a wired telephone station, the local service provider is a cellular service provider while the second carrier could be a LEC that is connecting the network of the cellular service provider to a called party at the wired telephone station. Thus, it is possible for a telecommunications carrier to serve multiple roles, e.g., being the local service provider for some calls while being a second carrier for other calls.
Each telephone subscriber of a local service provider has associated with his telephone service a presubscribed default second carrier that was selected by or for the subscriber. The presubscribed default second carrier carries multiple-carrier calls originated from the subscriber's telephone unless the local service provider is instructed otherwise by way of the call-by-call entry of a telecommunications carrier code indicating which telecommunications carrier should carry the particular call. For any call for which a telecommunications carrier code is not entered, the default second carrier is typically identified based on the particular telephone link--illustratively represented herein by a wired telephone line but also including wireless (cellular), fiber optic or cable connections and any other link provided to connect telephones to local service providers-on which the local service provider received the call.
Continuing with the above-described interexchange call example, which represents the most common scenario at present, each subscriber to local telephone service from a LEC has associated with his telephone line a "primary interexchange carrier," or PIC. The local subscriber is said to be "PIC'd" to the associated IXC. The interexchange carrier to which a subscriber is PIC'd will be used by default to complete interexchange calls originated from his telephone line unless the LEC is instructed otherwise. Such instruction is given when the subscriber enters, on a call-by-call basis, prior to dialing the called telephone number, a telecommunications carrier code, illustratively an IXC access code, corresponding to the desired IXC. One such IXC access code is "10 2 8 8" (10 A T T) corresponding to AT&T.
Specifically, when a long-distance call is initiated by the subscriber from his telephone line, and no access code is entered prior to the dialing of the called telephone number, the call is routed through the network of the originating subscriber's LEC, over the network of the PIC'd IXC and, ultimately, through the network of the LEC which has as one of its subscribers the terminating subscriber. Alternatively, a subscriber may initiate a long-distance call by dialing, prior to supplying the called telephone number, an IXC access code that indicates which of the IXCs he wishes to carry his call. Upon receipt of the access code by a switch of the LEC serving the caller, it is recognized that the caller wishes his call to be carried over the IXC corresponding to the received access code. Accordingly, the LEC routes the caller's call to a trunk connecting the LEC to the IXC indicated by the access code, regardless of the IXC to which the caller's telephone line is PIC'd. Thereafter, the LEC passes the called telephone number to the selected IXC. It is noted that the supplying of an IXC access code typically indicates the selection by the caller of an IXC other than the one that he is PIC'd to, but occasionally it may indicate the same IXC to which the caller is PIC'd.
According to prior art arrangements, the information indicating whether a call was routed to a particular telecommunications carrier because a telecommunications carrier code was supplied by the caller, as opposed to the caller having selected that particular telecommunications career by default, is never conveyed to the particular telecommunications carrier. Such information could prove useful and valuable to a telecommunications carrier, especially in the area of providing special services. Therefore, in accordance with the principles described in concurrently filed U.S. patent application Ser. No. 08/086,975, if a telecommunications carrier code specifying a particular telecommunications carrier is supplied by a caller, the network of the local service provider routing such a can to the specified telecommunications carrier is arranged to transmit to the network of the selected telecommunications carrier an indication that a telecommunications carrier code was supplied by the caller to the local service provider. For example, the indication is transmitted as a signaling system 7 (SS7) message, or a portion thereof. Moreover, the local service provider may also provide an indication that the carrier whose telecommunications carrier code was entered is not the carrier that would have been selected by default for the calling telephone line.
Furthermore, in accordance with the principles described in concurrently filed U.S. patent application Ser. No. 08/086,956, a telecommunications carrier is arranged to provide different call treatment for a call, e.g., different call features or services, when the telecommunications carrier receives an indication that the telecommunications carrier's telecommunications carrier code was entered by the caller, as compared to the treatment the telecommunications carrier provides for the same call when such an indication is not received. According to one such service, the "follow me anywhere" service, if a caller placing a call to the subscriber's telephone prefixes the call with the telecommunications carrier code of the telecommunications carrier, the telecommunications carrier completes the call to the telephone corresponding to a telephone number previously specified by the subscriber. If the caller places the call without prefixing the call with the telecommunications carrier code of the telecommunications carrier, the call is completed to the subscriber's telephone. According to another such service, if a caller's call cannot be completed and the caller prefixed his call with the telecommunications carrier code of a telecommunications carrier, then the caller is supplied with a voice mailbox in which he can store a message that can later be retrieved by the called pay. In one embodiment, the telecommunications carrier is an interexchange carrier and the telecommunications carrier code is an IXC access code.
As articulated in the above-cited patent applications, loss of service for non-local service provider activated features can occur if a called party who is a subscriber to such services, e.g., the "follow me anywhere" service, is a subscriber of the same local service provider as the calling pasty. This is because calls between such parties are local calls that are typically dialed without the prefixing of such calls with a telecommunications carrier code, the calls being processed only by the common local service provider. As such, the non-local service provider never gets a chance to invoke its "follow me anywhere" service and the local service provider is not aware that calls to such a subscriber are to be forwarded to another telephone. However, by prefixing even local calls with a telecommunications carrier code, the non-local service provider can check its data base to determine if special processing is to be provided for even a non-long-distance call. If the called party had indeed subscribed to the "follow me anywhere" service, and had stored a telephone number of a telephone to which his calls are to be routed that is not served by the same local service provider that is serving the calling party, the non-local service provider would complete the call to the designated telephone. But, if the called party had subscribed to the "follow me anywhere" service, and had stored the telephone number of a telephone to which his calls are to be routed that is served by the same local service provider as is the calling party, the non-local service provider would supply to the local service provider the stored telephone number. The local service provider could then complete the call to the telephone indicated by the stored telephone number. Moreover, I have recognized that requiring a caller to enter a telecommunications carrier code for each call for which he wishes non-default treatment is cumbersome.